Bioprosthetic heart valve implantation device

ABSTRACT

In general, the present invention comprises an holding apparatus for facilitating implantation of a prosthetic heart valve within a mammalian heart. The holding apparatus generally comprises a cage or enclosure having a heart valve prosthesis retention space defined therewith. The proximal end of the holding apparatus is releasably attached to the proximal end of the heart valve prosthesis such that, when the holding apparatus is advanced in a forward direction, a &#34;pulling&#34; force will be exerted upon the proximal end of the prosthesis, rather than a &#34;pushing&#34; force being exerted upon the distal end of the prosthesis. The releasable attachment of the prosthesis to the holding apparatus may be accomplished by any suitable attachment member, and preferably comprises a number of suture threads which are passed through the prosthesis and threaded upon the holding apparatus at location(s) which are easily accessible such that the surgeon may cut the suture threads to effect release of the heart valve prosthesis, during the prosthesis implantation procedure. Also described and claimed are associated methods for utilizing the above-described holding apparatus to effect implantation of a prosthetic heart valve.

FIELD OF THE INVENTION

The present invention relates generally to medical devices, and moreparticularly to an apparatus for facilitating the implantation of astentless bioprosthetic, (e.g., xeno raft, homograft, allograft) heartvalve, and associated methodology.

BACKGROUND OF THE INVENTION

Among the various types of prosthetic heart valves which have heretoforebeen known are certain "stentless" bioprosthetic valves. One example ofa stentless bioprosthetic heart valve is described in U.S. Pat. No.5,197,979 (Quintero, et. al.), the entire disclosure of which is herebyexpressly incorporated by reference.

One such stentless bioprosthetic valve is commercially available as theEdwards® PRIMA™ stentless aortic bioprosthesis (Baxter Edwards AG,Spierstrasse 5, GH6048 Horn, Switzerland). This stentless aorticbioprosthesis generally comprises a chemically-tanned porcine aorticheart valve having an adjacent segment of aorta connected thereto. Aninflow annulus is defined at the proximal end of the bioprosthesis andan outflow annulus is defined at the distal end thereof. The porcinecoronary arteries are cut away from the aortic portion of thebioprosthesis, thereby forming coronary openings in the bioprosthesis.Woven polyester cloth is sewn around the inflow annulus of thebioprosthesis to facilitate suturing of the proximal end of thebioprosthesis to a surgically prepared endogenous aortic valve root ofthe recipient patient. Thereafter, in cases wherein the entirebioprosthesis is implanted the distal end of the bioprosthesis may beanastomosed to the patient's aorta, and the coronary openings of thebioprosthesis are aligned with, and sutured to, the patient's coronaryostia.

In an alternative implantation procedure, the surgeon may elect to trimor cut away the distal portion of the cylindrical prosthesis body (e.g.,that portion above the valve leaflets), and to implant only the proximalportion of the bioprosthesis. In such modified "partial" implantationprocedure, it is unnecessary for the surgeon to anastomose that distalend of the distal end of the bioprosthesis and/or the coronary openingsto the patient's aorta because such distal portions of the bioprosthesishave been trimmed or cut away prior to its implantation.

The above-described stentless aortic bioprosthesis of U.S. Pat. No.5,197,979 (Quintero, et al.) was provided with a holding fixture whichwas attached to the outflow (i.e., distal) end of the bioprosthesis. Anelongate handle was connectable to the holding fixture. Such handle wasintended to be grasped and manipulated by the surgeon to maneuver thestentless aortic bioprosthesis to its desired implantation position.Certain problems or shortcomings were, however, associated with thisholding fixture attached to the outflow (i.e., distal) end of thebioprosthesis. First, the holding fixture was of a configuration whichtended to substantially block the outflow end of the prosthetic valveroot cylinder, thereby preventing the surgeon from visualizing the valveleaflets from a distal vantage point, during the implantation procedure.Second, because the holding fixture was attached only to the outflow(i.e., distal) end of the stentless bioprosthesis, the exertion offorward pressure against the holding fixture tended to cause thecylindrical body and/or leaflets of the stentless bioprosthesis tocompressively deform or buckle, due to the pliable or flexible nature ofsuch stentless bioprosthesis. Such buckling or deformation of thestentless bioprosthesis could be problematic if one were to attempt, inaccordance with standard operative technique, to advance the stentlessbioprosthesis over a series of pre-placed suture threads which have beenpassed through the inflow annulus at the inflow (i.e., proximal) end ofthe bioprosthesis.

In view of the above-described problems associated with the prior artholding fixtures used in conjunction with stentless bioprosthesis, it isdesirable to develop an improved holding apparatus which is attachableto the inflow annulus located at the inflow (i.e., proximal) end of thebioprosthesis such that, when proximally directed pressure is exertedagainst the holding apparatus, such pressure will be transferred throughthe holding apparatus so as to effect a "pulling" action upon the inflowannulus at the inflow (i.e., proximal) end of the bioprosthesis, ratherthan a "pushing" action upon the outflow (i.e., distal) end of thebioprosthesis. Furthermore, it is desirable for such improved holdingapparatus to be configured and constructed in a manner which does notsubstantially block the outflow opening at the outflow (i.e., distal)end of the bioprosthesis, thereby allowing the surgeon to clearly viewand properly orient the valve leaflets and commissurae of thebioprosthesis during the implantation procedure. Also, it is desirablethat the holding apparatus be constructed in a manner which firmly holdsthe stentless bioprosthesis during any trimming or cutting away of thedistal portion of the bioprosthesis, as is sometimes done in themodified or partial implantation technique described hereabove.

SUMMARY OF THE INVENTION

In general, the present invention provides a prosthetic heart valveholding apparatus which comprises a cage or enclosure whichsubstantially surrounds a prosthetic heart valve, and which isreleasably attachable to the proximal end of the prosthetic heart valve.A handle may be attachable to the holding apparatus to facilitateadvancement of the heart valve to its desired implantation site. Becausethe cage or enclosure of the holding apparatus is attached to theprosthetic heart valve at or near its proximal end, the exertion offorwardly directed advancement force upon the holding apparatus (e.g.,by pushing on a handle attached to the holding apparatus ) will beconverted into a "pulling" force on the proximal portion of theprosthesis rather than a "pushing" force on the distal end thereof.

In accordance with the invention, the holding apparatus may generallycomprise a) a distal hub member and b) a plurality of strut memberswhich extend downwardly from said distal hub member at spaced-apartlocations around. The downwardly extending strut members define aprosthetic heart valve receiving space beneath the distal hub member andinboard of the strut members. A bioprosthetic heart valve (e.g., astentless bioprosthesis) having an annular sewing ring (e.g., a dacronmesh ring) at its proximal end is insertable within the receiving spacesuch that the bottom ends of the strut members may be connected orattached to or immediately above the sewing ring, at the proximal end ofthe prosthesis. A handle may be formed upon, or may be attachable to,the distal hub member of the holding apparatus such that the handleextends upwardly therefrom. A surgeon may then grasp the handle, and mayutilize the handle to advance the holding apparatus (with the heartvalve prosthesis releasably mounted therewithin) to the intendedimplantation site. Because the holding apparatus is connected at or nearthe proximal (inflow) end of the prosthesis, the exertion of pushingforce on the handle will cause a "pulling" force to be applied to theproximal (inflow) end of the prosthesis rather than exerting a "pushing"force against the distal (outflow) end of the prosthesis. In thismanner, the holding apparatus allows the bioprosthesis to be advancedinto position without compressively deforming or collapsing theprosthesis, and without any need for use of extraneous instruments(e.g., forceps) to grasp and pull the proximal (inflow) end of thebioprosthesis into place. After the proximal (inflow) end of thebioprosthesis has been positioned immediately adjacent the endogenousvalve root or other intended site of implantation, sutures may be tiedin place to affix the sewing ring at the proximal (inflow) end of theprosthesis to the endogenous valve root or other host tissue.Thereafter, the prosthesis is disconnected and detached from the holdingapparatus, and the holding apparatus is extracted and removed therebyremoving the bioprosthesis in its implanted position within the hostbody.

Further in accordance with the invention, a proximal ring member may beformed at the proximal end of the holding apparatus, and sutures orother releasable connections may be formed directly between the proximalring member of the holding apparatus and the proximal (inflow) end ofthe prosthesis. In this manner, the proximal ring member formed on theholding apparatus will serve to rigidly maintain the proximal (inflow)end of the prosthesis in a rigidly fixed open configuration duringplacement of the sutures through the sewing ring of the prostheticvalve, and throughout the implantation procedure. The surgeon may theneffectively suture the proximal mesh ring of the prosthesis (e.g., theportion which protrudes below the proximal ring member of the holdingapparatus (to the body of the patient) while the proximal ring member ofthe holding apparatus holds the proximal (inflow) opening of theprosthesis in it's intended open configuration. Additionally, when theholding apparatus is being used in conjunction with a stentless aorticbioprosthesis or other aortic valve prosthesis of the type havingopenings which are intended to be sutured to the aortic tissue of thepatient about the coronary ostia, it may be desirable to provide aproximal ring member on the holding apparatus which is transectable orseverable into a plurality of segments. In this manner, thebioprosthesis may be sutured or otherwise affixed to the coronary ostiaof the patent before detachment and removal of the holding apparatus isaccomplished, and the gaps or openings which exist between separatesegments of the inferior ring member may be utilized as passagewaysthrough which the sutured interconnection between the bioprosthesis andthe coronary artery of the patient may pass. This will permit theholding apparatus to be extracted and removed from the patient evenafter the bioprosthesis has been securely sutured to the coronary ostiaof the patient. The openings which are created by segmenting of theproximal ring member may be utilized as passageways through which thepreviously-created interconnections between the bioprosthesis and thebody of the patient may pass. This allows the holding apparatus to beextracted and removed after the aortic bioprosthesis containedtherewithin has been suture or otherwise affixed to the coronary ostiaof the patient.

Still further in accordance with the invention, the holding apparatusoperates to rigidly support and hold the proximal end of thebioprosthesis in a fully opened, non-disfigured condition during theimplantation procedure. This aspect of the invention is particularlyprominent in embodiments which incorporate the above-described proximalring member which is literally attached fully around the proximal end ofthe bioprosthesis. By rigidly holding and supporting the bioprosthesisin its desired, open, non-disfigured condition the holding apparatus ofthe present invention serves to prevent the phenomenon of multipleplications during implantation of the stentless bioprosthesis. Byrigidly supporting and holding the proximal end of the bioprosthesis,the holding apparatus allows the surgeon to apply pressure to the sewingring portion of the bioprosthesis during passage of sutures andimplantation of the bioprosthesis without forming unwanted folds,plications, indentations or invaginations in the bioprosthesis. Thisensures that, when finally implanted, the bioprosthesis will be in itsdesired non-deformed configuration, thereby providing for optimalfunctionality of the bioprosthesis after implantation.

Still further in accordance with the invention, the holding apparatusmay be releasably connected to the bioprosthesis contained therewithinby any suitable type of releasible connecting member, apparatus, orsubstance. For example, the bioprosthesis may be releasably connected tothe holding apparatus by way of suture thread(s), clasp(s), clip(s),clamp(s), hook(s), strap(s), ligature(s), adhesive(s), magnet(s), etc.In the preferred embodiment described herebelow, suture threads areutilized to releasably attach the bioprosthesis to the holdingapparatus. Such suture threads are passed through apertures or holesformed at various locations on the holding apparatus, and are stitchedthrough the body of the bioprosthesis such that the proximal (inflow)end of the bioprosthesis is attached to the proximal end of the holdingapparatus, and further such that several points adjacent the distal endof the bioprosthesis are also attached to adjacent distal locations onthe holding apparatus. These suture threads are strung over adjacentlocations on the holding apparatus, such adjacent locations beingreadably accessible during the implantation procedure to permit thesurgeon to cut or sever the suture threads at such locations. Suchcutting or severing of the suture threads serves to release thebioprosthesis from the holding apparatus, thereby allowing the holdingapparatus to be extracted and removed.

Still further in accordance with the invention, the holding apparatusmay incorporate one or more hinges or bendable regions which permitflexing or relaxation of the functional shape of the holding apparatusto facilitate its intended use, extraction and removal.

Still further in accordance with the invention, the holding apparatusmay be constructed such that open areas are formed about the lateralsides of the bioprosthesis to permit the surgeon to optionally trim orcut away the distal portion of the bioprosthesis in cases wherein thesurgeon has elected to perform a modified "partial" bioprosthesisimplantation procedure. In this regard, suture threads or other markingsmay be formed on the bioprosthesis to mark a line above the distal-mostlocation(s) of the valve leaflets so that the surgeon may safely cutaway that portion of the bioprosthesis which extends above such suturethreads or other markings, without damaging the valve leaflets andwithout impairing the hemodynamic valving capability of thebioprosthesis.

Still further in accordance with the present invention, the holdingapparatus may comprise a hub member positionable adjacent the distal endof the prosthesis body, and a plurality of elongate strut members havingproximal ends and distal ends which are attached to the hub members suchthat the strut members extend substantially downward therefrom so as todefine a hollow prosthesis retention space inboard of the strut membersand beneath the hub member. Disposed on the proximal end of the strutmembers is an attachment ring for maintaining the prosthesis within theretention space. The proximal inflow end of the prosthesis is releasablyconnected to the attachment ring to allow the holding apparatus to beselectively disengaged from the prosthesis.

The attachment ring itself preferably comprises an inner ring memberwhich is attached to the proximal ends of the strut members, and anouter ring member which is releasably attached to the inner ring member.In this respect, a portion of the prosthesis is frictionally capturedbetween the inner and outer ring members. The application of a force ina distal direction to the hub member subsequent to the detachment of theinner ring member from the outer ring member facilitates the distalmovement of the inner ring member relative to the outer ring member,thereby resulting in the separation of the inner and outer ring membersfrom each other and the release of the portion of the prosthesis fromtherebetween.

The inner and outer ring members of the attachment ring are releasablyattached to each other by at least one suture thread extendingtherebetween. In this respect, the inner and outer ring members eachinclude at least one pair of suture passage apertures formed therein,with the suture passage apertures of one pair being coaxially alignedwith respective ones of the suture passage apertures of the other pairfor allowing the suture thread to be extended between the inner andouter ring members. Additionally, the inner and outer ring members eachpreferably include at least one enlarged attachment region formedthereon, with each pair of suture passage apertures being formed withina respective attachment region. The attachment region formed on theinner ring member preferably includes a cutting instrument receivingnotch formed therein which is sized and configured to permit a cuttinginstrument to be inserted thereinto for purposes of cutting the suturethread.

The inner ring member of the attachment ring defines a beveled outersurface portion, with the outer ring member defining a beveled innersurface portion having a configuration which is complementary to theouter surface portion of the inner ring member. In this respect, theportion of the prosthesis is frictionally captured between the outer andinner surface portions when the inner and outer ring members arereleasably attached to each other. Additionally, the outer ring memberof the attachment ring preferably includes at least one tab portionextending distally therefrom which is sized and configured to engage theinner ring member subsequent to the distal movement of the inner ringmember relative to the outer ring member in an amount sufficient torelease the portion of the prosthesis from therebetween. The outer ringmember preferably includes three (3) pairs of tab portions extendingdistally therefrom, with the tab portions of each pair being disposed oneither side of a respective one of the three (3) strut members of theholding apparatus when the inner and outer ring members are attached toeach other.

Further aspects and advantages of the invention will become apparent tothose skilled in the art upon reading and understanding of the detaileddescriptions of preferred embodiments set forth herebelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative and presently preferred embodiments of the invention areshown in the accompanying drawings in which:

FIG. 1 is a perspective view of a first embodiment of a bioprostheticaortic heart valve implantation system of the present invention;

FIG. 2 is a bottom plan view of the implantation system of FIG. 1;

FIG. 3 is an exploded perspective view of the implantation system ofFIG. 1;

FIG. 4 is an enlarged perspective view of a portion of the implantationsystem of FIG. 1;

FIG. 5a is a perspective view of a bioprosthetic aortic heart valveimplantation system and its packaging;

FIG. 5b is a perspective view of the system of FIG. 5a with a handle;

FIG. 5c is an enlarged perspective view of a retainer portion of thepackaging of FIG. 5a;

FIG. 5d is a perspective view of the implantation system of FIG. 5abeing prepared for use;

FIG. 5e is a perspective view of removal of an identification tag of theimplantation system of FIG. 5a;

FIG. 5f is a perspective view of a preparation step for the implantationsystem of FIG. 5a;

FIG. 5g is a perspective view of placed suture thread between theimplantation system of FIG. 5a and an aortic root;

FIG. 5h is a perspective view similar to that of FIG. 5g except with theimplantation system at the site of aortic root implantation;

FIG. 5i is an enlarged perspective view of a portion of the system ofFIG. 5a showing a suture thread retainer with suture thread therein;

FIG. 5j is an enlarged elevation view along line 5j--5j of FIG. 5i; and

FIG. 5k is a perspective view of an implanted heart valve of theimplantation system of FIG. 5a along with the holding apparatus thereofbeing withdrawn after valve prosthesis placement.

FIG. 6a is an exploded, perspective view of a second embodiment of thebioprosthetic aortic heart valve implantation system of the presentinvention.

FIG. 6b is an assembled perspective view of the second embodiment of thebioprosthetic heart valve implantation system of the present inventionshown in FIG. 6a.

FIG. 6c is an enlarged perspective showing of the upper end of one ofthe strut members of the apparatus of FIG. 6a, wherein a tab formed onthe upper end of the strut member has been bent over to facilitateattachment of the strut member to the distal hub of the apparatus.

FIG. 7 is a perspective view of a third embodiment of a bioprostheticaortic heart valve implantation system of the present invention.

FIG. 8 is an exploded, perspective view of the third embodiment of thebioprosthetic heart valve implantation system shown in FIG. 7.

FIG. 9a is an enlarged, partial perspective view of the region 9aencircled in FIG. 7.

FIG. 9b is a cross-sectional view taken along 9b--9b of FIG. 9a, showingthe attachment ring of the implantation system as releasably attached tothe bioprosthetic aortic heart valve.

FIG. 9c is a cross-sectional view similar to FIG. 9b, but showing theattachment ring of the implantation system as detached from thebioprosthetic aortic heart valve.

FIG. 10a is a cross-sectional view taken along line 10a--10a of FIG. 7.

FIG. 10b is a cross-sectional view similar to FIG. 10a, but showing theattachment ring of the implantation system as detached from thebioprosthetic aortic heart valve.

FIG. 11a is a cross-sectional view taken along line 11a--11a of FIG. 7.

FIG. 11b is a cross-sectional view similar to FIG. 11a, but showing theattachment ring of the implantation system as detached from thebioprosthetic aortic heart valve.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The accompanying figures show three (3) different embodiments of theimplantation system 10, 10a, 10b of the present invention. Theindividual elements and aspects of these embodiments are independentlycombinable and interchangeable. However, it will generally beappreciated that the first embodiment shown in FIGS. 1-5 is routinelyuseable in procedures wherein the implantation system 10 of the presentinvention is detached and removed from the bioprosthetic heart valvebefore the body of the bioprosthesis is sutured to or otherwiseconnected to the coronary ostia of the patient. On the other hand, thesecond and third embodiments of the implantation system 10a, 10b areprimarily usable in procedures wherein the implantation system 10a, 10bis permitted to remain attached to the bioprosthesis during the processof suturing or otherwise attaching the bioprosthesis to the coronaryostia, and thereafter, the implantation system 10a, 10b is detached andremoved from the patient without disrupting the previously-formedanastomosis or connection between the bioprosthesis and the coronaryostia.

i. First Embodiment

FIGS. 1-5, show a first embodiment of a bioprosthetic heart valveimplantation system 10 of the present invention. The implantation system10 shown in FIG. 1-5 includes a holding apparatus 12 having a stentlessbioprosthetic heart valve 54 mounted therewithin.

The preferred holding apparatus 12 comprises a distal central hub member14 whose center is in alignment with a longitudinal axis LA of theholding apparatus 12, and an proximal ring member 20 having a series ofapertures 22 formed therein, at spaced apart locations therearound. Eachaperture 22 is capable of having a suture thread passed therethrough.Although the embodiment shown in the drawings includes a total of 24apertures 22 formed in the proximal ring member 20, the actual number ofsuch apertures 22 may vary, and may in some embodiments number fewerthan 24. Typically 18-24 of these apertures 22 will be utilized.

The preferred holding apparatus 12 has three strut members 24 whichextend outwardly and downwardly (i.e., in the proximal direction) fromthe central hub member 14 to the ring member 20. Each of the three strutmembers 24 may be positioned directly opposite one of the three cusps orcommissurae of the prosthetic valve. It will be appreciated, however,that the specific number of strut members 24 may not be critical to theinvention, and various designs of the holding apparatus 12 may beemployed wherein, as an alternative to the use of individual strutmembers 24, the holding apparatus body may be a cylindrical or bulbouscage or enclosure formed of solid, perforated, mesh or other suitablematerial, configured to substantially surround the distal end and sidesof the prosthesis retention space 52.

Also, it will be appreciated that the proximal ring member 20 shown inthe drawings is an optional feature. Such proximal ring member 20 servesto substantially distribute the pulling force evenly around the inflowannulus at the proximal end of the prosthesis. Various alternativeembodiments of the invention may be devised which do not include suchproximal ring member 20 and wherein the proximal ends of the strutmembers themselves, are sewn or otherwise attached to the prosthesis 54,at discrete points or locations therearound, or the proximal end of anycontinuous cage or enclosure used to form the holding apparatus 12 maybe releasably attached at individual, discrete locations around theinflow annulus of the prosthesis 54.

As is apparent from the figures, the diameter of the ring member 20 ispreferably larger than the diameter of the distal hub member 14. In theembodiment shown, each strut member 24 is made up of a substantiallyvertical first segment 26 and a substantially horizontal second segment30. The substantially vertical first segments 26 of the strut members 24extend upwardly from the proximal ring member 20. The substantiallyhorizontal second segment 30 of each strut member 24 extends laterallyoutward from the distal hub member 14.

A suture thread retainer 28 is formed on each strut member 24. Eachsuture thread retainer 28 incorporates a traversing notch or channel 38within which a plurality of suture threads may be retained. A cuttinginstrument entrance slot 46 is formed within each strut member 24 topermit scissors and other types of suitable instruments to be insertedthereinto, for the purpose of simultaneously cutting one or more suturethreads which are disposed within the channel 38.

As shown in significant detail of FIG. 5j, each channel 38 formed byeach suture thread retainer 36 comprises an outer wall 40, an inner wall42 and a floor 44. The manner in which the first and second suturethreads 70, 78 are disposed within channels 38 is described more fullyherebelow.

The distal hub member 14 is, in the embodiments shown, a generallycylindrical member having a threaded bore 48 formed therein. Thethreaded bore 48 is sized and configured to receive a handle member 50(FIGS. 5b-5f). Examples of handle members 50 which may be used includehandle Model 1108 or handle Model 1111 available from Baxter HealthcareCorporation, Edwards CVS Division, 17221 Red Hill Ave., P.O. Box 11150,Irvine, Calif. 92711-1150. The outer diameter of the distal hub member14 is sufficiently small so as not to substantially block or obscure theoutflow opening at the distal end of the prosthesis 54 when theprosthesis 54 is positioned within the prosthesis retention space 52 ofthe holding apparatus 12.

The prosthesis retention space 52 is formed between or inboard of thestrut members 24 and ring member 20, and below (i.e., proximal to) thedistal hub member 14. The bioprosthesis 54 is releasably mounted withinthe retention space 52 of the holding apparatus 12. The bioprosthesis 54shown in the drawings is a stentless aortic bioprosthesis whichcomprises a cylindrical prosthesis body 56 having a plurality of valveleaflets 62 disposed therein. The outer surface of these cylindricalprosthesis body 56 may incorporate a marking thread, such as agreen-colored thread, which is located immediately distal to the valveleaflets 62. This marking thread 60 will thus serve as a guide to permitoptional trimming away of the distal portion of the cylindricalprosthesis body 56 without injuring the valve leaflets 62.

A ring of woven polyester mesh 64 is sewn to the inflow annulus of theprosthesis 54, and may extend beneath the proximal ring 20 of the cage,as shown. Such ring of polyester mesh material 64 facilitates suturingof the prosthesis 54 to the endogenous aortic root. An additional flap68 of woven polyester mesh material may be sewn on a portion of theouter surface of the cylindrical prosthesis body 56, to further enhancethe suture-holding of the prosthesis to specific endogenous tissue. Asused herein, reference to the cylindrical body 56 of the prosthesis 54is intended to include the polyester mesh ring 64 and polyester meshflap 68 attached to the tissue of the prosthesis 54.

The prosthesis 54 is releasably mounted within the retention space 52 byfirst 70 and second 78 suture threads. The specific manner in which thefirst 70 and second 78 suture threads are utilized to releasably attachthe bioprosthesis 54 to the holding apparatus 12 can be seen from FIGS.1 and 4. As shown, the first suture thread 70 is initially tied aboutthe upper surface of the proximal ring member 20, immediately adjacentone of the suture package apertures 22. Thereafter, the first suturethread 70 is alternately laced in and out of the apertures 22, and isthereby passed through the under-lying cylindrical prosthesis body 56,as shown. Upon exiting the suture passage aperture 22 which is closestto each strut member 24, the first suture thread 70 is pulled upwardly,and is passed through the channel 38 of the suture thread retainer 36formed on that strut member 24. Thereafter, the first suture thread 70is pulled downwardly adjacent the opposite side of that strut member 24and is then laced in and out of the previously unused suture passageapertures 22 adjacent that side of the strut member 24, to grasp theunderlying cylindrical prosthesis body 56. The free end of the firstsuture thread 70 is then tied and knotted over the upper surface of theproximal ring member 20, in the same manner as had been done with theother end of that first suture thread 70. This is shown in FIG. 4.

The second suture thread 78 is knotted around the undersurface of theupper arm 30 of each strut member 24, and is then passed through theunderlying cylindrical body 56 of the prosthesis 54, and through thechannel. 38 of the suture thread retainer 36, as shown, The leading endof the second suture thread 78 may optionally then be again passedthrough the underlying cylindrical body 56 of the prosthesis 54 a secondtime, and will thereafter be passed through the adjacent suture passageaperture 34 and tied beneath the undersurface of the upper arm 30 of thestrut member 24, as shown. In this regard, the second suture thread 78serves to accomplish releasable attachment of the distal aspect of thebioprosthesis 52 to the holding apparatus 12.

The specific manner in which the first suture thread 70 and secondsuture thread 78 are disposed within the suture retainer 36 are shown indetail in FIG. 5i-5j. With reference to FIGS. 5i-5j it can be seen thatthe channel 38 formed within the suture retainer 36 is defined by aninner wall 42, a base 44, and an outer wall 40. The first suture thread70 and second suture thread 78 are positioned within the channel 38 ofthe suture retainer 36 in side-by-side juxtaposition. Thus, the surgeonmay insert a single cutting instrument 108, such as scissors, into thecutting instrument receiving slot 46 of each strut member 24 for thepurpose of simultaneously severing both the first suture thread 70 andthe second suture thread 78 associated with that particular strut member24. In this regard, only three cutting operations are necessary toeffectively sever all three of the first suture threads 70 and all threeof the second suture threads 78, thereby releasing the bioprosthesis 54from its attachment to the holding apparatus 12.

The preferred methodology by which the first embodiment of theimplantation system 10 may be utilized to facilitate surgicalimplantation of the bioprosthesis 54 is shown in FIGS. 5a-5j. Withreference to FIGS. 5a-5j, the implantation system 10 is packaged asshown in FIG. 5a in a sterile plastic jar 86 with a plastic retainer 88having a tab 90. The jar 86 contains buffered glutaraldehyde 92. Agloved hand 93 is used to remove the system 10 from the jar 86 bygrasping the tab 90 of the retainer 88. The retainer 88 has a track 94which releasably retains the hub member 14 by engaging a groove 16thereof. Once the implantation system 10 is removed from the jar 86, thehandle member 50 is threaded into the threaded bore 48 of the hub member14. The handle member 50 is then grasped and, as shown in FIG. 5c, theretainer 88 is discarded. The valve prosthesis 54 housed within theprosthesis retention space 52 is rinsed in several fresh sterile salinesolutions 96 as known in the art and exemplified in FIG. 5d, and itsidentification tag 98 is removed as shown in FIG. 5e and retained forrecord keeping. To prevent drying of the prosthesis 54 prior toimplantation, sterile saline may be applied, as illustrated in FIG. 5f,every one to two minutes until implantation.

FIGS. 5g-5h show one method of initially positioning and securing theinflow annulus of the prosthesis 54 at a supra-annular implantation siteimmediately above the endogenous aortic root 100. As shown, thebioprosthesis 54, while it remains releasably mounted within the holdingapparatus 12 is positioned at an exteriorized location immediately abovethe upper scissor receiving notch 102. Suture threads 104 are passedthrough the polyester mesh ring 64 sewn to the inflow annulus of theprosthesis 54, through the endogenous aortic root 100, and againupwardly through the polyester mesh ring 64. After such suture threads104 have been installed all the way around the endogenous aortic root100 and the prosthesis 54, proximally directed pressure is applied tothe handle 50, so as to advance the holding apparatus 12 and theprosthesis 54 downwardly over the pre-positioned suture threads 104, toa point (FIG. 5h) where the inflow annulus of the prosthesis 54 is inits desired supra annular position immediately above the endogenousaortic root 100.

Thereafter, as shown in FIG. 5i-5j, scissors 108 will be inserted intoeach of the cutting instrument receiving slots 46, and will be utilizedto simultaneously cut the first 70 and second 78 suture threadsextending through the channel 38 of the suture retainers 36 formed oneach strut member 24. In this regard, only three scissor snips will berequired to effect cutting of all three first suture threads 70 as wellas all three second suture threads 78. Because both ends of each firstsuture thread 70, and both ends of each second suture thread 78, aretied and anchored to the holding apparatus 12, the subsequent extractionand pulling away of the holding apparatus 12 will also serve to draw thefirst suture threads 70 and second suture thread 78 out of theprosthesis 54. In this regard, the severed first suture thread 70 andsecond suture thread 78 will be withdrawn and carried away with the usedholding apparatus 12, as shown in FIG. 5k.

After the holding apparatus 12 has been removed and discarded, thesurgeon may tie and cut away excess quantities of the suture threads104, and may effect any additional suturing required to secure thedistal end of the prosthesis 54 and/or the coronary openings 55 to thepatient's coronary ostia.

ii. Second Embodiment

In the second embodiment of the holding apparatus 12a, as shown in FIGS.6a-6c, the proximal ring members 20a is segmented or divided into aplurality of separate portions. The vertical strut members 24a arecapable of being splayed or bent outwardly in directions which aregenerally divergent from one another, so as to cause the individualsegments or portions of the proximal ring member 20a to spread apartfrom one another. This results in the formation of gaps or openings inthe proximal ring member 20a, so as to allow the proximal ring member20a to be extracted from the patient even after the bioprosthesiscontained within the holding apparatus 12a has been sutured to thecoronary ostia of the patient.

More specifically, the second embodiment of the holding apparatus 12amay be constructed as a single molded piece, or alternately may befabricated from a plurality of individual components as is specificallyillustrated in the exploded view of FIG. 6a. With reference to FIG. 6a,the individual components of which the holding apparatus 12a is formedcomprise a central hub member 14a and three (3) strut members 24a havingrespective segments of the proximal ring member 20a formed on the basalor proximal end thereof.

In the embodiment shown, the central hub member 14a is provided withthree outwardly extending attachment legs 90 each such attachment leg 90has a substantially horizontal, planar central portion 92 with verticalflanges or lips 90 formed on either side thereof. Scissor-receivingnotches or cut-away areas 96 extend inwardly into each of the horizontalflat center portions 92 of the attachment legs 90.

Pass-through slots 97 are formed in each of the attachment legs 90,inboard of each horizontal flat central portions 92. Correspondingbendable tab members 100 are formed on the upper ends of the strutmembers 24a, and such tab members 100 are passable downwardly throughthe pass-through slots 97 of the attachment legs 90. Thereafter, suchtab members 100 may be bent upwardly such that they abut against theunder surface of the horizontal flat portion 92 of each attachment leg90. This effectively and firmly attaches each strut member 24a to thecentral hub member 14a.

Separate upper scissor receiving notches 102, 104 are formed in theupper ends of the strut members 24a. As the tab members 100 are bentover, each of these upper scissor receiving notches 102, 104 becomesaligned with the corresponding notch 96 formed in the adjacentattachment leg 90 of the central hub member 14a, to facilitate insertionof scissors or other cutting instruments to sever the upper suturethread 116 passed through suture passage apertures 112 or otherattachment member or apparatus by which the upper end of each strutmember 24a is attached to the bioprosthesis 54 positioned within theprosthesis retention space 52a holding apparatus 12a. The preferredmanner in which such upper suture threads 116 are deployed andpositioned is shown in detail in FIG. 6, and is more fully describedherebelow.

Each of the three (3) segments of the proximal ring member 20a shown inFIG. 6a have ends 110 which are abutable against one another such thatthe proximal ring member 20a will assume the assembled shape of asubstantially round or circular ring. Locator projections 113 extendfrom some of the segment ends 110 of the proximal ring member 20a toassist in guiding and locating the ends 110 into direct abutment to formthe desired ring structure.

As shown in FIG. 6, individual lower suture threads 120 may be utilizedto secure the assembled proximal ring member 20a to a bioprosthesis 54contained within the interior prosthesis receiving space 52a of suchholding apparatus 12a.

In this regard, discrete groups of suture passage apertures 112 arelocated at specific locations on the holding apparatus 12a to facilitatereleasible attachment of the holding apparatus 12a to a bioprosthesiswhich is positioned within the prosthesis retention space 52a of theholding apparatus 12a.

Preferably, a group of four (4) suture passage apertures 112 is formedin a substantially rectangular array near the upper end of each strutmember 24a, at a location immediately adjacent the basal end of eachupper scissor-receiving notch 102. In this manner, the upper suturethreads 116 may be tied or otherwise anchored to the strut members 24a,and passed alternately in and out of the four (4) suture passageapertures 112, as shown in FIG. 6b, to thereby stitch or couple theupper end of each strut member 24a to a bioprosthesis 54 containedwithin the prosthesis retention space 52a. When it is desired todisconnect the bioprosthesis from the holding apparatus 12a, scissorsmay be inserted downwardly into the upper scissor receiving notches 102,so as to cut the upper suture thread 116, thereby releasing thebioprosthesis from the upper ends of the strut members 24a.

Similarly, groups consisting of four (4) suture passage apertures 112are formed at spaced-apart locations around the proximal ring member20a, and individual lower suture threads 120 may be tied or otherwiseanchored to the suture passage aperture 112, and may be passedalternately in and out of the adjacent four (4) suture passage apertures112 to stitch the bioprosthesis 54 within the retention space 52a to theproximal ring member 20a, as shown in FIG. 6b. Because the lower scissorreceiving notches 118 extend downwardly into the upper edges of theproximal ring member 20a, at the locations between the suture passageapertures 112 of a discrete group, the tip of a pair of scissors orother cutting instrument may be inserted into each such scissorreceiving notch 118 to cut each lower suture thread 120 by which theproximal ring member 20a is attached to the proximal end of thebioprosthesis. In this regard, six separate scissor snips may beutilized to completely severe all of the individual lower 120 suturethreads 120 which attach the proximal ring member 20a to the proximalend of the bioprosthesis 54.

As with the first embodiment of the invention shown in FIGS. 1-5, thebioprosthesis 54 is positioned within the prosthesis retention space 52aof the holding apparatus 12a such that the proximal mesh ring 64 of thebioprosthesis 54 protrudes below the lower edge of the proximal ringmember 20a. Such mounting of the bioprosthesis 54 within the retentionspace 52a is preferably accomplished prior to packaging within a storagecontainer 86, as shown in FIG. 5a. This enables the surgeon to easilyuse the holding apparatus 12a to facilitate proper placement andsuturing of the proximal sewing ring 64 of the bioprosthesis 54 to thepatient prior to release or removal of the holding apparatus 12a.

In operation, the second embodiment of the holding apparatus 12a shownin FIGS. 6a-6c operates in substantially the same way as describedhereabove with respect to the first embodiment shown in FIGS. 1-5.However, the second embodiment of the holding apparatus 12a has theadded capability of being removed after the coronary openings 55 (seeFIG. 3) of the bioprosthesis 54 have been anastomosed or otherwiseattached to the coronary ostia of the patient. For example, after theholding apparatus 12a of the second embodiment (along with abioprosthesis 54 mounted within its prosthesis retention space 52a) hasbeen advanced to a point where the proximal mesh ring 64 of thebioprosthesis is located at its intended implantation site (e.g., theaortic annular or supra-annular position) and sutured in place, thesurgeon may then proceed to suture, or otherwise attach the peripheriesof the coronary openings 55 of the bioprosthesis to the aortic tissuesurrounding the coronary ostia of the patient. Thereafter, scissors areinserted downwardly into the upper scissor receiving notches 102 and maybe utilized to cut the upper suture thread 116, thereby enabling theupper suture thread 116 to be pulled through the body of the prosthesissuch that the holding apparatus may be extracted and removed from theprosthesis. Also, scissors are inserted downwardly into each of thelower scissor receiving notches 118 formed in the proximal ring member20a, and will be utilized to cut each of the lower suture thread 120,thereby enabling the lower suture thread 120 to be pulled through andremoved from the body of the prosthesis as the holding apparatus 12a isextracted and removed.

After all of the upper suture threads 116 and lower suture threads 120have been cut, the surgeon will splay or outwardly bend the strutmembers 24a away from one another so as to cause the ends 110 of theproximal ring member 20a segments to separate or part from one another.This creates gaps or openings between the adjacent ends 110 of theseparate segments of the proximal ring member 20a. After such gaps oropenings have been created in the proximal ring member 20a, the surgeonwill lift upwardly on a handle which is attached to the central opening48a of the central hub member 14a, thereby lifting the entire holdingapparatus 12a upwardly. Such upward lifting of the holding apparatus 12acauses the previously severed upper suture threads 116 and lower suturethreads 120 to be drawn or pulled through the adjacent tissue of theprosthesis, thereby freeing the holding apparatus 12a. Furthermore, asthe holding apparatus 12a is lifted upwardly, the points at which theprosthesis are connected to the aortic tissue surrounding the coronaryostia will pass through the gaps or openings created between theadjacent ends 110 of separate segments of the proximal ring member 20a.In this manner, the holding apparatus 12a is extracted and removed fromthe body of the patient while the bioprosthesis remains in its implantedposition with the coronary openings 55 of the bioprosthesis 54 beinganastomosed or otherwise attached to the patient.

iii. Third Embodiment

Referring now to FIGS. 7-11b, there is depicted a holding apparatus 12bconstructed in accordance with a third embodiment of the presentinvention. As shown in FIG. 7, the holding apparatus 12b includes thestentless bioprosthetic heart valve or prosthesis 54 mountedtherewithin.

Such mounting of the prosthesis 54 within the holding apparatus 12b ispreferably accomplished prior to packaging of the bioprosthesis 54within a storage solution 92, as shown in FIG. 5a. As in the holdingapparatus 12, 12a constructed in accordance with the first and secondembodiments of the present invention, the holding apparatus 12b includesa central hub member 14b. The hub member 14b itself includes a femaleretention bore 130 formed therein to facilitate the attachment of thepreviously described handle member 50 to the holding apparatus 12b.Extending radially outward from the hub member 14b in equidistantlyspaced intervals of approximately 120 degrees are three (3) identicallyconfigured attachment legs 132.

In addition to the hub member 14b and integral attachment legs 132, theholding apparatus 12b includes three (3) elongate strut members 134having distal ends which are attached to the outermost ends ofrespective ones of the attachment legs 132. As best seen in FIG. 8, thestrut members 134 may define arcuately contoured, outwardly bowedcentral portions. The strut members 134 extend substantially downwardfrom the attachment legs 132 so as to define a hollow prosthesisretention space inboard of the strut members 134 and beneath the hubmember 14b. As seen in FIG. 7, this retention space is sized andconfigured to accommodate the prosthesis 54.

The holding apparatus 12b of the third embodiment further comprises anattachment ring 136 which is disposed on the proximal ends of the strutmembers 134 for maintaining the prosthesis 54 within the retention spacedefined within the holding apparatus 12b. As will be discussed in moredetail below, the proximal inflow end of the prosthesis 54 is releasablyconnected to the attachment ring 136 in a manner allowing the holdingapparatus 12b to be selectively disengaged from the prosthesis 54subsequent to the placement thereof into a desired site.

In the third embodiment, the attachment ring 136 itself comprises aninner ring member 138 which is attached to the proximal ends of thestrut members 134. The inner ring member 138 includes a lower, beveledouter surface portion 140 and an upper, beveled inner surface portion142 which defines the top rim 144 of the inner ring member 138. Formedon the top rim 144 of the inner ring member 138 are three (3) attachmentlugs 146 which are used to facilitate the attachment of the proximalends of the strut members 134 to the inner ring member 138. As such, theattachment lugs 146 are oriented about the periphery of the top rim 144in equidistantly spaced intervals of approximately 120 degrees.

In addition to the attachment lugs 146, formed on the top rim 144 of theinner ring member 138 are three (3) enlarged attachment regions 148. Inthe third embodiment, each attachment region 148 is centrally positionedbetween a respective pair of the attachment lugs 146. As such, like theattachment lugs 146, the attachment regions 148 are preferably separatedfrom each other by equidistantly spaced intervals of approximately 120degrees. As best seen in FIG. 9a, each attachment region 148 includes aspaced pair of suture passage apertures extending therethrough which areseparated by a cutting instrument receiving notch 150, the use of whichwill be discussed in more detail below.

In addition to the inner ring member 138, the attachment ring 136 of theholding apparatus 12b includes an outer ring member 152 which isreleasably attached to the inner ring member 138. As will also bediscussed in more detail below, a portion of the prosthesis 54 isfrictionally captured between the outer and inner ring members 152, 138when they are releasably attached to each other. The outer ring member152 is adapted to receive the inner ring member 138 in a nestingfashion, and includes a beveled inner surface portion 154 having aconfiguration which is complementary to the outer surface portion 140 ofthe inner ring member 138. Additionally, as with the inner ring member138, formed about the top edge of the outer ring member 152 inequidistantly spaced intervals of approximately 120 degrees are three(3) enlarged attachment regions 156. As best seen in FIG. 9a, extendingthrough each of the attachment regions 156 is a spaced pair of suturepassage apertures 158.

In the third embodiment, the releasable attachment of the inner andouter ring members 138, 152 to each other is facilitated by initiallyinserting the inner ring member 138 into the outer ring member 152 suchthat the attachment regions 148 of the inner ring member 138 arevertically aligned with respective ones of the attachment regions 156 ofthe outer ring member 152. When so aligned, the suture passage aperturesof each pair disposed within a respective attachment region 148 arecoaxially aligned with respective ones of the suture passage apertures158 of the corresponding attachment region 156. As further seen in FIG.9a, a suture thread 159 is extended through the coaxially aligned suturepassage apertures of each corresponding pair of attachment regions 148,156 to facilitate the releasable attachment of the inner and outer ringmembers 138, 152 to each other.

As best seen in FIGS. 7 and 8, the outer ring member 152 of theattachment ring 136 further includes three (3) spaced pairs of tabportions 160 which extend distally from the top rim thereof. Each pairof tab portions 160 is centrally positioned between a respective pair ofattachment regions 156. In this respect, when the inner and outer ringmembers 138, 152 are releasably attached to each other in theaforementioned manner, each pair of tab portions 160 is oriented so asto receive a respective one of the attachment lugs 146 of the inner ringmember 138 therebetween. As such, when the inner and outer ring members138, 152 are releasably attached to each other, the tab portions 160 ofeach pair extend upwardly along either side of a respective strut member134 of the holding apparatus 12d. Each tab portion 160 of the outer ringmember 152 has a generally hook-shaped configuration, and defines achannel 162 which is directed downwardly toward the beveled innersurface portion 154 of the outer ring member 152.

Referring now to FIGS. 9b-11b, the prosthesis 54 with which the holdingapparatus 12b is preferably utilized includes the layer of mesh 64 whichis sewn to and extends about the inflow annulus thereof. Importantly,the mesh 64 defines an excess end portion 164 which extends along, butis not secured to, the outer surface of the prosthesis 54 adjacent theinflow annulus thereof. As previously explained, the prosthesis 54 ismaintained within the retention space of the holding apparatus 12b bythe releasable connection of the attachment ring 136 to the prosthesis54. In the holding apparatus 12b, the releasable connection of theattachment ring 136 to the prosthesis 54 is facilitated by thefrictional capture of the end portion 164 of the mesh 64 between thecomplementary beveled outer and inner surface portions 140, 154 of theinner and outer ring members 138, 152 when releasably attached to eachother in the aforementioned manner. The frictional retention of the endportion 164 between the inner and outer ring members 138, 152, and inparticular the outer and inner surface portions 140, 154 thereof, isshown in FIGS. 9b, 10a and 11a. When it is desired to disengage theholding apparatus 12b from the prosthesis 54 subsequent to the placementthereof in a desired site, the inner and outer ring members 138, 152 aredetached from each other so as to allow the end portion 164 of the mesh64 to be released from compression between the beveled outer and innersurface portions 140, 154.

The detachment of the inner and outer ring members 138, 152 from eachother is facilitated by cutting each of the three (3) suture threads 159extending between corresponding pairs of the attachment regions 148,156. Such cutting is accomplished by inserting the end of a cuttinginstrument into the notches 150 of the attachment regions 148 insuccession, and severing the suture threads 159. After the suturethreads 159 have been severed by the cutting instrument, the applicationof force in a distal direction to the hub member 14b facilitates thedistal movement of the inner ring member 138 relative to the outer ringmember 152. Such distal movement results in the separation of the innerand outer ring members 138, 152 from each other, and the release of theend portion 164 from therebetween. Such distal movement of the innerring member 138 relative to the outer ring member 152 which facilitatesthe release of the end portion 164 from therebetween is best shown inFIG. 9c.

As will be recognized, subsequent to the release of the end portion 164from between the inner and outer ring members 138, 152, it is stillnecessary that the outer ring member 152 be withdrawn from within theoperative site along with the inner ring member 138. Despite thedetachment of the inner ring member 138 from the outer ring member 152facilitated by the severing of the suture threads 159, the outer ringmember 152 is pulled from the operative site by the inner ring member138 due to the inclusion of the tab portions 160 on the outer ringmember 152.

As best seen in FIGS. 10a-11b, the tab portions 160 of the outer ringmember 152 engage the inner ring member 138 subsequent to the distalmovement of the inner ring member 138 relative to the outer ring member152 in an amount sufficient to release the end portion 164 of the mesh64 from therebetween. In this respect, subsequent to such distalmovement of the inner ring member 138, the top rim 144 thereof isreceived into the channels 162 of the tab portions 160, thus causing thecontinued distal movement of the inner ring member 138 to effectivelydraw the outer ring member 152 therewith. As a result, when the top ring144 of the inner ring member 138 is received into the channels 162 ofthe tab portions 160, a sufficient gap is defined between the outer andinner surface portions 140, 154 so as to facilitate the release of theend portion 164 from therebetween. Thus, the holding apparatus 12b movesindependently of the prosthesis 54.

It is to be appreciated that the invention has been described hereabovewith reference to certain presently preferred embodiments and examplesonly, and no effort has been made to exhaustively describe all possibleembodiments and examples of the invention. Indeed, various adaptationsand modifications may be made to the specific embodiments describedhereabove, without departing from the intended spirit and scope of theinvention. Accordingly, it is intended that all reasonable modificationsand alterations to the above-described embodiments and examples, beincluded within the scope of the following claims.

What is claimed is:
 1. A holding apparatus for facilitating the surgicalimplantation of a heart valve prosthesis of the type having, i) agenerally tubular prosthesis body having an inner surface, an outersurface, a proximal end, a distal end, an inflow annulus at the proximalend thereof, an outflow annulus at the distal end thereof, and ii) aplurality of valving members disposed within the prosthesis body toperform a hemodynamic valving function and a sewing ring attached to theinflow annulus to facilitate suturing of the inflow annulus to anendogenous opening, said holding apparatus comprising:a) a hub memberpositionable adjacent the distal end of the prosthesis body b) aplurality of elongate strut members having proximal ends and distal endswhich are attached to said distal hub member such that the strut membersextend substantially downward therefrom so as to define a hollowprosthesis retention space inboard of said strut members and beneathsaid hub member; c) at least one releasable attachment means forreleasably holding the prosthesis within said prosthesis retention spacesuch that the proximal inflow end of the prosthesis is connected to thestrut members; and d) a proximal ring member attached to the proximalends of said strut members, said proximal ring member being attachableabout the proximal inflow annulus of the prosthesis such that, when aforce is applied in the proximal direction against the distal hub memberof the holding apparatus, such force will be transferred through saidstrut members to said proximal ring member, thereby resulting in theapplication of a distally directed pulling force which is annularlydistributed about the proximal inflow annulus of the prosthesis.
 2. Theholding apparatus of claim 1, further comprising:an elongate handleattachable to the distal hub member of the holding apparatus, andextendable in a distal direction therefrom.
 3. The holding apparatus ofclaim 2 wherein said distal hub member has a female retention boreformed therein and wherein said elongate handle member has a distal malemember formed thereon, the distal male member of said handle beingengageable within the female retention bore of the distal hub member toeffect attachment of said handle to said holding apparatus.
 4. Theholding apparatus of claim 1 wherein:said proximal ring member issevered at at least two locations such that said proximal ring membermay be separated into a plurality of segments; and, said strut membersbeing bendable to cause the proximal ring member to separate such thatspaces are created between the segments of said ring member.
 5. Theholding apparatus of claim 1 further comprising:at least one releasableattachment member for temporarily connecting the inflow annulus at theproximal end of a heart valve prosthesis disposed within said hollowprosthesis retention space, to the proximal ends of the strut members;said releasable attachment member being manually disconnectable fromsaid prosthesis in a manner which releases the holding apparatus fromsaid prosthesis.
 6. The holding apparatus of claim 5 wherein:said atleast one releasable attachment member comprises a suture threadanchored to the holding apparatus and passable through a prosthesiswhich is disposed within the hollow prosthesis retention space, toreleasably attach said prosthesis to said holding apparatus; a portionof said suture thread being located upon the holding apparatus at afirst location which is sufficiently accessible during the implantationprocedure to permit cutting of said suture thread at said firstlocation, thereby causing the prosthesis to be disconnected from theholding apparatus such that the holding apparatus may be subsequentlyextracted and removed, leaving the heart valve prosthesis in place. 7.The holding apparatus of claim 6 wherein said holding apparatus furthercomprises:a cutting instrument retention notch formed in said holdingapparatus at said first location; said cutting instrument retentionnotch being sized to permit a cutting instrument to be insertedthereinto for the purpose of cutting of said suture thread at said firstlocation.
 8. The holding apparatus of claim 6 wherein:a plurality offirst suture threads are connected to the proximal ends of the strutmembers of the holding apparatus and are passed through the inflowannulus at the proximal end of a heart valve prosthesis disposed withinthe hollow prosthesis retention space of the holding apparatus, toconnect the distal ends of the strut members to the inflow annulus ofthe prosthesis; and, a plurality of second suture threads areadditionally anchored to the distal hub member of the holding apparatusand are passed through the heart valve prosthesis at locations which aredistal to the proximal end of the prosthesis, to effect furtherconnection of the prosthesis to the holding apparatus; said first suturethreads and said second suture threads being passed through said firstlocation and positioned in side-by-side juxtaposition, such that saidfirst suture threads and said second suture threads may be concurrentlysevered by a cutting instrument at said first location.
 9. The holdingapparatus of claim 8 wherein a suture retainer is formed on each of saidstrut members, and wherein said first suture threads and said secondsuture threads are passed through said suture retainer in side-by-sidejuxtaposition, such that said first and second suture threads may besimultaneously cut by a single cutting action performed at the locationof said suture retainer.
 10. The holding apparatus of claim 9 wherein acutting instrument receiving slot is formed in said holding apparatus,in the region of said suture retainer, to permit a cutting instrument tobe inserted for the purpose of cutting said first and second suturethreads at the location of said suture retainer.
 11. The holdingapparatus of claim 9 wherein said suture retainers are located adjacentthe distal end of the holding apparatus so as to be easily accessibleduring the implantation procedure.
 12. The holding apparatus of claim 1wherein:said at least one strut member comprises three strut membersspaced substantially equidistant from one another.
 13. The holdingapparatus of claim 1 wherein:said proximal ring member has a pluralityof suture-passage apertures extending therethrough to facilitatesuturing of said proximal ring member to the proximal end of aprosthesis disposed within said hollow prosthesis retention space. 14.The holding apparatus of claim 1 wherein a series of suture passageapertures are formed in said proximal ring member, on either side ofeach strut member, to permit a suture thread to be passed therethroughfor the purpose of releasably attaching said proximal ring member to theinflow annulus of a heart valve prosthesis positioned within theprosthesis retention space of the holding apparatus.
 15. The holdingapparatus of claim 14 wherein 18-24 of said suture passage apertures areformed in said proximal ring member.
 16. A heart valve prosthesisimplantation system comprising the holding apparatus of claim 1, furtherin combination with a heart valve prosthesis disposed within theprosthesis retention space of said holding apparatus.
 17. The system ofclaim 16 wherein said heart valve prosthesis is a stentless porcinebioprosthesis.
 18. The system of claim 16 wherein said plurality ofvalving members disposed within the cylindrical prosthesis body comprisetricuspid valve leaflets.
 19. The system of claim 18 wherein said heartvalve prosthesis further comprises:markers formed on said cylindricalprosthesis body, distal to said valve leaflets, to guide the optionalcutting of the prosthesis body to remove a distal portion of theprosthesis body without injuring the valve leaflets.
 20. A stentlessaortic heart valve system incorporating the holding apparatus of claim1, said system comprising:a holding apparatus according to claim 1; astentless aortic bioprosthesis comprising a generally tubular prosthesisbody having an inflow annulus at the proximal end thereof, an outflowannulus at the distal end thereof, a plurality of valving membersdisposed therewithin to hemodynamically valve blood passing through thetubular prosthesis body, and a mesh ring attached to the inflow annulusof the bioprosthesis; said bioprosthesis being positioned within theprosthesis retention space of the holding apparatus, such that the meshring of the bioprosthesis protrudes beyond the proximal end of theholding apparatus.
 21. The stentless aortic bioprosthesis system ofclaim 20 herein:a proximal ring member is formed on the bottom ends ofthe elongate strut members of the holding apparatus, said proximal ringmember having a plurality of suture passage apertures formed therein;and, at least one suture thread being passed in and out of the suturepassage apertures formed in the proximal ring member of the holdingapparatus and through the prosthesis body to effect releasableattachment of the proximal ring member of the holding apparatus to theprosthesis while the prosthesis is positioned within the retention spaceof the holding apparatus.
 22. The stentless aortic bioprosthesis systemof claim 21 wherein the proximal ring member of the holding apparatus isseparable into a plurality of segments after it has been disconnectedfrom the prosthesis.
 23. The holding apparatus of claim 1 wherein thehub member positionable adjacent the distal end of the prosthesis bodyis configured so as not to block the entire outflow annulus of thebioprosthesis positioned within the holding apparatus, thereby allowingone to see the orientation of the valve leaflets by looking downwardlythrough the outflow annulus of the bioprosthesis.
 24. The holdingapparatus of claim 1 wherein said plurality of elongate strut membersand said releasable attachments are attached about the bioprosthesis insuch a manner as to rigidly hold the bioprosthesis in a fully openconfiguration, thereby deterring the formation of plications in thebioprosthesis during the implantation procedure.
 25. A method forimplanting a prosthetic heart valve having a generally cylindricalprosthesis body, an inflow aperture formed at a proximal end of thegenerally cylindrical prosthesis body, an outflow aperture formed at thedistal end of the prosthesis body, a plurality of valving membersdisposed within the prosthesis body, and a longitudinal axis projectablelongitudinally through the prosthesis body, said method comprising thesteps of:a) providing a holding apparatus which comprises a rigidholding apparatus body having a distal end, a proximal end and a hollowheart valve prosthesis retention space defined therewithin, and areleasable attachment member for releasably connecting a heart valveprosthesis mounted within the prosthesis retention space, to the holdingapparatus; b) positioning the heart valve prosthesis within theprosthesis retention space of the holding apparatus said heart valveprosthesis having a distal end and a proximal end, an outflow annulusbeing formed at the proximal end thereof; c) utilizing the releasableattachment member to temporarily connect at least the proximal end ofthe holding apparatus to at least the proximal end of the prosthesis; d)positioning the holding apparatus, with the heart valve prosthesisreleasably mounted therewithin, a spaced distance away from an intendedimplantation site in the body of a patient with the proximal end of theprosthesis closest to the implantation site; e) passing a plurality ofsuture threads through the intended implantation site in the body of thepatient and through the inflow annulus of the heart valve prosthesis; f)pushing the distal end of the body toward the implantation site, toadvance the holding apparatus, with the heart valve prosthesisreleasably mounted therein, over the previously placed suture threads,to a position where the inflow annulus of the heart valve prosthesis isin contact with the intended implantation site within the body of thepatient; g) causing the releasable connection member to release theheart valve prosthesis from its connection with the holding apparatus;and h) extracting and removing the holding apparatus, leaving the heartvalve prosthesis at the intended implantation site.
 26. The method ofclaim 25 wherein said method further comprises:i) tying and cutting thepreviously placed suture threads to secure the inflow annulus of theheart valve prosthesis to the intended implantation site of the patient.27. The method of claim 26 wherein said method further comprises thestep of:suturing the outflow aperture at the distal end of the heartvalve prosthesis to the body of the patient, at a location which isdownstream of the site at which the inflow aperture of the prosthesiswas sutured to the body of the patient.
 28. The method of claim 27wherein the bioprosthesis has right and left coronary openings formedtherein at locations which correspond to the right and left coronaryostia of the patient, and wherein the method further comprises the stepof:j) suturing the coronary openings of the prosthesis to the aortictissue of the patient such that coronary openings of the prosthesis arein alignment with the patient's coronary ostia, thereby allowing aportion of the blood which passes out of the outflow annulus of theprosthesis to flow into the coronary arteries of the patient.
 29. Themethod of claim 28 wherein the holding apparatus provided in step a ofthe method has a unitary proximal ring member which is attached to theproximal portion of the prosthesis while the prosthesis is positionedwithin the retention space of the holding apparatus, and wherein step hof the method is performed before step j of the method.
 30. The methodof claim 28 wherein the holding apparatus provided in step a has asegmented ring member which is attached by releasable connection to aproximal portion of the bioprosthesis while the bioprosthesis ispositioned within the retention space of the holding apparatus, saidring member being subsequently separable into a plurality of segmentssuch that gaps exist between said ring member segments, and wherein:stepj of the method is performed prior to step h of the method, and step his modified to include separation of the segments of the proximal ringmember, and extraction of the holding apparatus such that the suturedconnection between the coronary openings of the prosthesis and theaortic tissue of the patient will remain intact and will pass throughthe gaps which have been created between the segments of the proximalring member.
 31. A holding apparatus for facilitating the surgicalimplantation of a heart valve prosthesis of the type having, i) agenerally tubular prosthesis body having an inner surface, an outersurface, a proximal end, a distal end, an inflow annulus at the proximalend thereof, an outflow annulus at the distal end thereof, and ii) aplurality of valving members disposed within the prosthesis body toperform an hemodynamic valving function and a sewing ring attached tothe inflow annulus to facilitate suturing of the inflow annulus to anendogenous opening, said holding apparatus comprising:a) a hub memberpositionable adjacent the distal end of the prosthesis body; b) aplurality of elongate strut members having proximal ends and distal endswhich are attached to said hub member such that the strut members extendsubstantially downward therefrom so as to define a hollow prosthesisretention space inboard of said strut members and beneath said hubmember; c) an attachment ring disposed on the proximal ends of the strutmembers for maintaining the prosthesis within said prosthesis retentionspace, the proximal inflow end of the prosthesis being releasablyconnected to the attachment ring to allow the holding apparatus to beselectively disengaged from the prosthesis, said attachment ring furthercomprising:an inner ring member attached to the proximal ends of thestrut members; and an outer ring member releasably attached to the innerring member, a portion of said prosthesis being frictionally capturedbetween the inner and outer ring members; wherein the application of aforce in a distal direction to the hub member subsequent to thedetachment of the outer ring member from the inner ring memberfacilitates the distal movement of the inner ring member relative to theouter ring member thereby resulting in the separation of the inner andouter ring members from each other and the release of the portion of theprosthesis from therebetween.
 32. The holding apparatus of claim 31,further comprising:an elongate handle attachable to the hub member ofthe holding apparatus, and extendable in a distal direction therefrom.33. The holding apparatus of claim 32 wherein said hub member has afemale retention bore formed therein and wherein said elongate handlemember has a distal male member formed thereon, the distal male memberof said handle being engageable within the female retention bore of thehub member to effect attachment of said handle to said holdingapparatus.
 34. The holding apparatus of claim 31 wherein said inner andouter ring members are releasably attached to each other by at least onesuture thread extending therebetween.
 35. The holding apparatus of claim34 wherein said inner and outer ring members each include at least onepair of suture passage apertures formed therein, the suture passageapertures of one pair being coaxially aligned with respective ones ofthe suture passage apertures of the other pair for permitting the suturethread to be extended between the inner and outer ring members.
 36. Theholding apparatus of claim 35 wherein said inner and outer ring memberseach include at least one enlarged attachment region formed thereon,each pair of the suture passage apertures being formed within arespective attachment region.
 37. The holding apparatus of claim 36wherein the attachment region formed on the inner ring member includes acutting instrument receiving notch formed therein which is sized andconfigured to permit a cutting instrument to be inserted thereinto forpurposes of cutting the suture thread.
 38. The holding apparatus ofclaim 31 wherein:said inner ring member defines a beveled outer surfaceportion; and said outer ring member defines a beveled inner surfaceportion having a configuration which is complementary to the outersurface portion of the inner ring member; the portion of the prosthesisbeing frictionally captured between the outer and inner surface portionswhen the inner and outer ring members are releasably attached to eachother.
 39. The holding apparatus of claim 31 wherein said outer ringmember includes at least one tab portion extending distally therefromwhich is sized and configured to engage the inner ring member subsequentto the distal movement of the inner ring member relative to the outerring member in an amount sufficient to release the portion of theprosthesis from therebetween.
 40. The holding apparatus of claim 39wherein:said at least one strut member comprises three strut membersspaced substantially equidistantly from one another.
 41. The holdingapparatus of claim 40 wherein said outer ring member includes three (3)pairs of tab portions extending distally therefrom, the tab portions ofeach pair being disposed on either side of a respective one of the strutmembers when the inner and outer ring members are attached to eachother.
 42. A heart valve prosthesis implantation system comprising theholding apparatus of claim 31, further in combination with a heart valveprosthesis disposed within the prosthesis retention space of saidholding apparatus.
 43. The system of claim 42 wherein said heart valveprosthesis is a stentless porcine bioprosthesis.
 44. The system of claim42 wherein said plurality of valving members disposed within thecylindrical prosthesis body comprise tricuspid valve leaflets.
 45. Thesystem of claim 44 wherein said heart valve prosthesis furthercomprises:markers formed on said cylindrical prosthesis body, distal tosaid valve leaflets, to guide the optional cutting of the prosthesisbody to remove a distal portion of the prosthesis body without injuringthe valve leaflets.
 46. A stentless aortic heart valve systemincorporating the holding apparatus of claim 31, said systemcomprising:a holding apparatus according to claim 31; a stentless aorticbioprosthesis comprising a generally tubular prosthesis body having aninflow annulus at the proximal end thereof, an outflow annulus at thedistal end thereof, a plurality of valving members disposed therewithinto hemodynamically valve blood passing through the tubular prosthesisbody, and a mesh ring attached to the inflow annulus of thebioprosthesis; said bioprosthesis being positioned within the prosthesisretention space of the holding apparatus, such that the mesh ring of thebioprosthesis protrudes beyond the proximal end of the holdingapparatus.
 47. The holding apparatus of claim 31 wherein the hub memberpositionable adjacent the distal end of the prosthesis body isconfigured so as not to block the entire outflow annulus of thebioprosthesis positioned within the holding apparatus, thereby allowingone to see the orientation of the valve leaflets by looking downwardlythrough the outflow annulus of the bioprosthesis.
 48. The holdingapparatus of claim 31 wherein said attachment ring is attached to thebioprosthesis in such a manner as to rigidly hold the bioprosthesis in afully open configuration, thereby deterring the formation of plicationsin the bioprosthesis during the implantation procedure.
 49. A method forimplanting a prosthetic heart valve having a generally cylindricalprosthesis body, an inflow aperture formed at a proximal end of thegenerally cylindrical prosthesis body, an outflow aperture formed at thedistal end of the prosthesis body, a plurality of valving membersdisposed within the prosthesis body, and a longitudinal axis projectablelongitudinally through the prosthesis body, said method comprising thesteps of:a) providing a holding apparatus which comprises a rigid bodyhaving a distal end, a proximal end and a hollow heart valve prosthesisretention space defined therewithin, and an attachment ring disposed onthe proximal end of the body for releasably connecting a heart valveprosthesis mounted within the prosthesis retention space to the holdingapparatus. b) positioning the heart valve prosthesis within theprosthesis retention space of the holding apparatus, said heart valveprosthesis having a distal end and a proximal end, an outflow annulusbeing formed at the proximal end thereof; c) utilizing the attachmentring to temporarily connect at least the proximal end of the body to atleast the proximal end of the prosthesis; d) positioning the holdingapparatus, with the heart valve prosthesis releasably mountedtherewithin, a spaced distance away from an intended implantation sitein the body of a patient with the proximal end of the prosthesis closestto the implantation site; e) passing a plurality of suture threadsthrough the intended implantation site in the body of the patient andthrough the inflow annulus of the heart valve prosthesis; f) pushing thedistal end of the body toward the implantation site, to advance theholding apparatus, with the heart valve prosthesis releasably mountedtherein, over the previously placed suture threads, to a position wherethe inflow annulus of the heart valve prosthesis is in contact with theintended implantation site within the body of the patient; g) causingthe attachment ring to release the heart valve prosthesis from itsconnection with the holding apparatus; and h) extracting and removingthe holding apparatus, leaving the heart valve prosthesis at theintended implantation site.
 50. The method of claim 49 wherein saidmethod further comprises:i) tying and cutting the previously placedsuture threads to secure the inflow annulus of the heart valveprosthesis to the intended implantation site of the patient.
 51. Themethod of claim 50 wherein said method further comprises the stepof:suturing the outflow aperture at the distal end of the heart valveprosthesis to the body of the patient, at a location which is downstreamof the site at which the inflow aperture of the prosthesis was suturedto the body of the patient.
 52. The method of claim 51 wherein thebioprosthesis has right and left coronary openings formed therein atlocations which correspond to the right and left coronary ostia of thepatient, and wherein the method further comprises the step of:j)suturing the coronary openings of the prosthesis to the aortic tissue ofthe patient such that the coronary openings of the prosthesis are inalignment with the patient's coronary ostia, thereby allowing a portionof the blood which passes out of the outflow annulus of the prosthesisto flow into the coronary arteries of the patient.
 53. A holdingapparatus for facilitating the surgical implantation of a heart valveprosthesis of the type having, i) a generally tubular prosthesis bodyhaving an inner surface, an outer surface, a proximal end, a distal end,an inflow annulus at the proximal end thereof, an outflow annulus at thedistal end thereof, and ii) a plurality of valving members disposedwithin the prosthesis body to perform a hemodynamic valving function anda sewing ring attached to the inflow annulus to facilitate suturing ofthe inflow annulus to an endogenous opening, said holding apparatuscomprising:a) a hub member positionable adjacent the distal end of theprosthesis body b) a plurality of elongate strut members having proximalends and distal ends which are attached to said distal hub member suchthat the strut members extend substantially downward therefrom so as todefine a hollow prosthesis retention space inboard of said strut membersand beneath said hub member; c) at least one releasable attachment meansfor releasably holding the prosthesis within said prosthesis retentionspace such that the proximal inflow end of the prosthesis is connectedto the strut members; d) a plurality of first suture threads anchored tothe proximal ends of the strut members of the holding apparatus, thefirst suture threads being passed through the inflow annulus at theproximal end of a heart valve prosthesis disposed within the hollowprosthesis retention space of the holding apparatus to connect theproximal ends of the strut members to the inflow annulus of theprosthesis; and, e) a plurality of second suture threads anchored to thedistal hub member of the holding apparatus, the second suture threadsbeing passed through the heart valve prosthesis at locations which aredistal to the proximal end of the prosthesis to effect furtherconnection of the prosthesis to the holding apparatus, wherein, aportion of each of said first and second suture threads being passedthrough and positioned in side-by-side juxtaposition at first locationson the holding apparatus which are sufficiently accessible during theimplantation procedure to permit concurrently severing by a cuttinginstrument of said first and second suture threads at said firstlocations, thereby causing the prosthesis to be disconnected from theholding apparatus such that the holding apparatus may be subsequentlyextracted and removed, leaving the heart valve prosthesis in place. 54.The holding apparatus of claim 53 wherein a suture retainer is formed oneach of said strut members, and wherein said first suture threads andsaid second suture threads are passed through said suture retainer inside-by-side juxtaposition, such that said first and second suturethreads may be simultaneously cut by a single cutting action performedat the location of said suture retainer.
 55. The holding apparatus ofclaim 54 wherein a cutting instrument receiving slot is formed in saidholding apparatus, in the region of said suture retainer, to permit acutting instrument to be inserted for the purpose of cutting said firstand second suture threads at the location of said suture retainer.
 56. Aholding apparatus for facilitating the surgical implantation of a heartvalve prosthesis of the type having, i) a generally tubular prosthesisbody having an inner surface, an outer surface, a proximal end, a distalend, an inflow annulus at the proximal end thereof, an outflow annulusat the distal end thereof, and ii) a plurality of valving membersdisposed within the prosthesis body to perform a hemodynamic valvingfunction and a sewing ring attached to the inflow annulus to facilitatesuturing of the inflow annulus to an endogenous opening, said holdingapparatus comprising:a) a hub member positionable adjacent the distalend of the prosthesis body and configured so as not to block the entireoutflow annulus of the bioprosthesis positioned within the holdingapparatus, thereby allowing one to see the orientation of the valveleaflets by looking downwardly through the outflow annulus of thebioprosthesis; b) a plurality of elongate strut members having proximalends and distal ends which are attached to said distal hub member suchthat the strut members extend substantially downward therefrom so as todefine a hollow prosthesis retention space inboard of said strut membersand beneath said hub member; and c) at least one releasable attachmentmeans for releasably holding the prosthesis within said prosthesisretention space such that the proximal inflow end of the prosthesis isconnected to the strut members.
 57. The holding apparatus of claim 56,further comprising:an elongate handle attachable to the distal hubmember of the holding apparatus, and extendible in a distal directiontherefrom.
 58. The holding apparatus of claim 57 wherein said distal hubmember has a female retention bore formed therein and wherein saidelongate handle member has a distal male member formed thereon, thedistal male member of said handle being engageable within the femaleretention bore of the distal hub member to effect attachment of saidhandle to said holding apparatus.
 59. The holding apparatus of claim 56further comprising:at least one releasable attachment member fortemporarily connecting the inflow annulus at the proximal end of a heartvalve prosthesis disposed within said hollow prosthesis retention space,to the proximal ends of the strut members; said releasable attachmentmember being manually disconnectable from said prosthesis in a mannerwhich releases the holding apparatus from said prosthesis.
 60. Theholding apparatus of claim 59 wherein:said at least one releasableattachment member comprises a suture thread anchored to the holdingapparatus and passable through a prosthesis which is disposed within thehollow prosthesis retention space, to releasably attach said prosthesisto said holding apparatus; a portion of said suture thread being locatedupon the holding apparatus at a first location which is sufficientlyaccessible during the implantation procedure to permit cutting of saidsuture thread at said first location, thereby causing the prosthesis tobe disconnected from the holding apparatus such that the holdingapparatus may be subsequently extracted and removed, leaving the heartvalve prosthesis in place.
 61. The holding apparatus of claim 60 whereinsaid holding apparatus further comprises:a cutting instrument retentionnotch formed in said holding apparatus at said first location; saidcutting instrument retention notch being sized to permit a cuttinginstrument to be inserted thereinto for the purpose of cutting of saidsuture thread at said first location.
 62. The holding apparatus of claim56 wherein:said at least one strut member comprises three strut membersspaced substantially equidistant from one another.
 63. A heart valveprosthesis implantation system comprising the holding apparatus of claim56, further in combination with a heart valve prosthesis disposed withinthe prosthesis retention space of said holding apparatus.
 64. The systemof claim 63 wherein said heart valve prosthesis is a stentless porcinebioprosthesis.
 65. A stentless aortic heart valve system incorporatingthe holding apparatus of claim 56, said system comprising:a holdingapparatus according to claim 56; a stentless aortic bioprosthesiscomprising a generally tubular prosthesis body having an inflow annulusat the proximal end thereof, an outflow annulus at the distal endthereof, a plurality of valving members disposed therewithin tohemodynamically valve blood passing through the tubular prosthesis body,and a mesh ring attached to the inflow annulus of the bioprosthesis;said bioprosthesis being positioned within the prosthesis retentionspace of the holding apparatus, such that the mesh ring of thebioprosthesis protrudes beyond the proximal end of the holdingapparatus.
 66. The stentless aortic bioprosthesis system of claim 65wherein:a proximal ring member is formed on the bottom ends of theelongate strut members of the holding apparatus, said proximal ringmember having a plurality of suture passage apertures formed therein;and, at least one suture thread being passed in and out of the suturepassage apertures formed in the proximal ring member of the holdingapparatus and through the prosthesis body to effect releasableattachment of the proximal ring member of the holding apparatus to theprosthesis while the prosthesis is positioned within the retention spaceof the holding apparatus.
 67. The stentless aortic bioprosthesis systemof claim 66 wherein the proximal ring member of the holding apparatus isseparable into a plurality of segments after it has been disconnectedfrom the prosthesis.
 68. A holding apparatus for facilitating thesurgical implantation of a heart valve prosthesis of the type having, i)a generally tubular prosthesis body having an inner surface, an outersurface, a proximal end, a distal end, an inflow annulus at the proximalend thereof, an outflow annulus at the distal end thereof, and ii) aplurality of valving members disposed within the prosthesis body toperform a hemodynamic valving function and a sewing ring attached to theinflow annulus to facilitate suturing of the inflow annulus to anendogenous opening, said holding apparatus comprising:a) a hub memberpositionable adjacent the distal end of the prosthesis body b) aplurality of elongate strut members having proximal ends and distal endswhich are attached to said distal hub member such that the strut membersextend substantially downward therefrom so as to define a hollowprosthesis retention space inboard of said strut members and beneathsaid hub member; and c) at least one releasable attachment means forreleasably holding the prosthesis within said prosthesis retention spacesuch that the proximal inflow end of the prosthesis is connected to thestrut members, wherein, said plurality of elongate strut members andsaid releasable attachments are attached about the bioprosthesis in sucha manner as to rigidly hold the bioprosthesis in a fully openconfiguration, thereby deterring the formation of plications in thebioprosthesis during the implantation procedure.
 69. The holdingapparatus of claim 68, further comprising:an elongate handle attachableto the distal hub member of the holding apparatus, and extendible in adistal direction therefrom.
 70. The holding apparatus of claim 69wherein said distal hub member has a female retention bore formedtherein and wherein said elongate handle member has a distal male memberformed thereon, the distal male member of said handle being engageablewithin the female retention bore of the distal hub member to effectattachment of said handle to said holding apparatus.
 71. The holdingapparatus of claim 68 further comprising:at least one releasableattachment member for temporarily connecting the inflow annulus at theproximal end of a heart valve prosthesis disposed within said hollowprosthesis retention space, to the proximal ends of the strut members;said releasable attachment member being manually disconnectable fromsaid prosthesis in a manner which releases the holding apparatus fromsaid prosthesis.
 72. The holding apparatus of claim 71 wherein:said atleast one releasable attachment member comprises a suture threadanchored to the holding apparatus and passable through a prosthesiswhich is disposed within the hollow prosthesis retention space, toreleasably attach said prosthesis to said holding apparatus; a portionof said suture thread being located upon the holding apparatus at afirst location which is sufficiently accessible during the implantationprocedure to permit cutting of said suture thread at said firstlocation, thereby causing the prosthesis to be disconnected from theholding apparatus such that the holding apparatus may be subsequentlyextracted and removed, leaving the heart valve prosthesis in place. 73.The holding apparatus of claim 72 wherein said holding apparatus furthercomprises:a cutting instrument retention notch formed in said holdingapparatus at said first location; said cutting instrument retentionnotch being sized to permit a cutting instrument to be insertedthereinto for the purpose of cutting of said suture thread at said firstlocation.
 74. The holding apparatus of claim 68 wherein:said at leastone strut member comprises three strut members spaced substantiallyequidistant from one another.
 75. A heart valve prosthesis implantationsystem comprising the holding apparatus of claim 68, further incombination with a heart valve prosthesis disposed within the prosthesisretention space of said holding apparatus.
 76. The system of claim 75wherein said heart valve prosthesis is a stentless porcinebioprosthesis.
 77. A stentless aortic heart valve system incorporatingthe holding apparatus of claim 68, said system comprising:a holdingapparatus according to claim 68; a stentless aortic bioprosthesiscomprising a generally tubular prosthesis body having an inflow annulusat the proximal end thereof, an outflow annulus at the distal endthereof, a plurality of valving members disposed therewithin tohemodynamically valve blood passing through the tubular prosthesis body,and a mesh ring attached to the inflow annulus of the bioprosthesis;said bioprosthesis being positioned within the prosthesis retentionspace of the holding apparatus, such that the mesh ring of thebioprosthesis protrudes beyond the proximal end of the holdingapparatus.
 78. The stentless aortic bioprosthesis system of claim 77wherein:a proximal ring member is formed on the bottom ends of theelongate strut members of the holding apparatus, said proximal ringmember having a plurality of suture passage apertures formed therein;and, at least one suture thread being passed in and out of the suturepassage apertures formed in the proximal ring member of the holdingapparatus and through the prosthesis body to effect releasableattachment of the proximal ring member of the holding apparatus to theprosthesis while the prosthesis is positioned within the retention spaceof the holding apparatus.
 79. The stentless aortic bioprosthesis systemof claim 78 wherein the proximal ring member of the holding apparatus isseparable into a plurality of segments after it has been disconnectedfrom the prosthesis.
 80. A stentless aortic heart valve systemincorporating a holding apparatus for facilitating the surgicalimplantation of a stentless heart valve prosthesis of the type having,i) a generally tubular prosthesis body having an inner surface, an outersurface, a proximal end, a distal end, an inflow annulus at the proximalend thereof, an outflow annulus at the distal end thereof, and ii) aplurality of valving members disposed within the prosthesis body toperform an hemodynamic valving function and a sewing ring attached tothe inflow annulus to facilitate suturing of the inflow annulus to anendogenous opening, said system comprising:a) a hub member positionableadjacent the distal end of the prosthesis body; b) a plurality ofelongate strut members having proximal ends and distal ends which areattached to said hub member such that the strut members extendsubstantially downward therefrom so as to define a hollow prosthesisretention space inboard of said strut members and beneath said hubmember; and c) an attachment ring disposed on the proximal ends of thestrut members for maintaining the prosthesis within said prosthesisretention space, the proximal inflow end of the prosthesis beingreleasably connected to the attachment ring to allow the holdingapparatus to be selectively disengaged from the prosthesis, saidstentless aortic bioprosthesis having a mesh ring attached to the inflowannulus of the bioprosthesis and being positioned within the prosthesisretention space of the holding apparatus, such that the mesh ring of thebioprosthesis protrudes beyond the proximal end of the holdingapparatus.
 81. A holding apparatus for facilitating the surgicalimplantation of a heart valve prosthesis of the type having, i) agenerally tubular prosthesis body having an inner surface, an outersurface, a proximal end, a distal end, an inflow annulus at the proximalend thereof, an outflow annulus at the distal end thereof, and ii) aplurality of valving members disposed within the prosthesis body toperform an hemodynamic valving function and a sewing ring attached tothe inflow annulus to facilitate suturing of the inflow annulus to anendogenous opening, said holding apparatus comprising:a) a hub memberpositionable adjacent the distal end of the prosthesis body andconfigured so as not to block the entire outflow annulus of thebioprosthesis positioned within the holding apparatus, thereby allowingone to see the orientation of the valve leaflets by looking downwardlythrough the outflow annulus of the bioprosthesis; b) a plurality ofelongate strut members having proximal ends and distal ends which areattached to said hub member such that the strut members extendsubstantially downward therefrom so as to define a hollow prosthesisretention space inboard of said strut members and beneath said hubmember; and c) an attachment ring disposed on the proximal ends of thestrut members for maintaining the prosthesis within said prosthesisretention space, the proximal inflow end of the prosthesis beingreleasably connected to the attachment ring to allow the holdingapparatus to be selectively disengaged from the prosthesis.
 82. Aholding apparatus for facilitating the surgical implantation of a heartvalve prosthesis of the type having, i) a generally tubular prosthesisbody having an inner surface, an outer surface, a proximal end, a distalend, an inflow annulus at the proximal end thereof, an outflow annulusat the distal end thereof, and ii) a plurality of valving membersdisposed within the prosthesis body to perform an hemodynamic valvingfunction and a sewing ring attached to the inflow annulus to facilitatesuturing of the inflow annulus to an endogenous opening, said holdingapparatus comprising:a) a hub member positionable adjacent the distalend of the prosthesis body; b) a plurality of elongate strut membershaving proximal ends and distal ends which are attached to said hubmember such that the strut members extend substantially downwardtherefrom so as to define a hollow prosthesis retention space inboard ofsaid strut members and beneath said hub member; and c) an attachmentring disposed on the proximal ends of the strut members for maintainingthe prosthesis within said prosthesis retention space, the proximalinflow end of the prosthesis being releasably connected to theattachment ring to allow the holding apparatus to be selectivelydisengaged from the prosthesis, wherein, said attachment ring isattached to the bioprosthesis in such a manner as to rigidly hold thebioprosthesis in a fully open configuration, thereby deterring theformation of plications in the bioprosthesis during the implantationprocedure.